Like others have suggested, Trackster, FinalSurge, Garmin Clipboard are 3 you can choose from depending on your preferences. FinalSurge will cost a subscription where others won't.
I'm using Garmin Clipboard this season as it meets what I want out of it. I don't use it to send workouts though which is something you mentioned was important to you, so I can't comment much on that feature.
In the end, pros and cons to each, so what works for one coach may not work for you. Good luck this season!